S e c o n d e d I t I o n 1 Reading for the Real World 1

extremely
fat. Even people who seem 
only 
slightly
overweight can actually be considered obese. If a person has a 
certain
amount of fat on their body, then their health might be in danger. This amount of fat 
is usually thought to be 40 percent of the body’s total 
composition
. Finding a 
person’s exact fat percentage is troublesome. Most people still rely on their weight 
measurement to tell them if they are overweight or obese.
There are problems with this method, however. There are 
recommended
weights for different ages. In addition, weight alone says nothing about a person’s 
percentage of body fat, which is most important. People have different body types, 
which can make weight measurements 
unreliable
. For instance, athletes usually 
have more muscle mass than other people. Muscle weighs more than fat. Therefore, 
an athlete may weigh more than their recommended weight, but this does not mean 
they are not healthy. A more accurate measurement of body fat is needed.
Probably the most popular method of determining body fat today is the 
Body Mass Index (BMI). BMI is a person’s weight (in kilograms) divided 
by the square of his or her height (in meters). For men, a BMI of 24 
to 27 is normal. For women, it is 23 to
26. A BMI of 30 or more means a 
1
obese --- overweight in an unhealthy way
8
extremely --- to the utmost degree; exceedingly; 
excessively
9
slightly --- a little
9
certain --- particular
11
composition --- a mix of all the various parts
14
recommend --- to suggest
17
unreliable --- not able to be trusted
Track 9
 

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30
35
40
45
person is obese. Many experts feel that BMI is a reliable way to determine if a 
person’s weight is unhealthy. However, others feel that BMI is too 
general
to be 
really useful. The numbers come from comparisons of large groups of people. It 
is not related to an individual’s body composition. BMI says nothing about a 
person’s actual percentage of body fat. There are many different ways that BMI 
can be affected by body shape and size. Muscular people may show a high BMI, 
even though they are perfectly healthy. Some people have higher bone 
density than others, which increases their weight. In some cases, those 
who have very low body fat and are also not muscular can have a BMI 
that is too high. BMI is also unreliable for children and the elderly. 
Even supporters of BMI think that it should not be used for people 
under eighteen or over seventy years old.
Despite these 
criticisms
, there are strong positive aspects of 
BMI. The main one is that it is very simple. The measurement can 
be performed easily. It does not take special knowledge or 
equipment. Though BMI is a general measurement, it still gives 
useful information. At least, it can suggest that there might be a 
problem. Furthermore, some studies have shown that people with 
higher BMI numbers have a higher risk of health problems. It takes only 
a minute to get a BMI number, but the